Yes. No matter what the conditions, you must obtain a burn permit from your local or state public health department and fire department before burning anything that exceeds the size of a recreational fire (3 feet wide and 2 feet high). Even with a burn permit, you must still check in with North Metro Fire personnel prior to burning to ensure conditions are safe to do so.
When we are under Level 1 Fire Restrictions, bonfires and most agricultural burning are prohibited.
When we are under a Level 2 Fire Ban, all outdoor burning involving solid fuels (wood, leaves, charcoal, etc.) is prohibited, regardless of size.